What function does butterfly wings and bird wings structures share?

Butterfly wings and bird wings both serve the primary function of enabling flight, allowing these creatures to navigate their environments, escape predators, and find food. While their structures differ—bird wings being composed of feathers and a bone framework, and butterfly wings made of chitin and covered in scales—they both exhibit adaptations for aerodynamics. Additionally, both types of wings play a role in thermoregulation and can serve as visual signals for mating or territorial displays.